For several years, a modest office building in a well-heeled neighborhood of Islamabad, Pakistan, has been the target of a secret CIA operation to capture Osama bin Laden, U.S. intelligence sources tell NBC News.
The building houses the local office of the al-Jazeera television network. Couriers have dropped off two tapes from bin Laden there over the past few years, tapes that offer some of the few clues to the whereabouts of the world's most-wanted man.
"The only connection that bin Laden has, that we know, with the outside world, is through video and audio tape," says Robert Grenier, a former director of the CIA's Counterterrorism Center and a former CIA station chief in Islamabad, who now works as a consultant for Kroll Inc.
U.S. counterterror sources tell NBC News that the CIA mounted an elaborate covert operation to track back those videotapes, through multiple handoffs by couriers, all the way to bin Laden.
The sources say the CIA traced bin Laden's last videotape, from October 2004, back to a village in Pakistan. From there, the CIA and its partners were able to capture a mid-level al-Qaida figure known as a skilled propagandist, but bin Laden remained elusive. An al-Jazeera official would not comment on the NBC News report.
At the National Counterterrorism Center (NCTC), bin Laden and the senior al-Qaida leadership remain a top priority. Every morning, top counterterror officials meet in the NCTC room to review the latest intelligence, including any new information on bin Laden. Senior intelligence officials acknowledge that the last time they knew with certainty where bin Laden was in real time was before 9/11.
Specifically, the fall of 2000 — that's when a CIA Predator drone beamed video back live from Afghanistan of a tall man in white robes, a figure surrounded by security guards who CIA analysts believe was bin Laden.
Intelligence officials tell NBC News that the recent search for bin Laden has centered on Pakistan's Chitral Valley and in the remote Nooristan region of Afghanistan.
NBC News recently shot rare footage in Nooristan. Local leaders deny bin Laden is on their turf, but they say there are plenty of radicalized youths who come to the area and are willing to fight for their vision of radical Islam.
"They are recruited by the Taliban, given the money and they are making some problems for us," says Tamim Nuristani, governor of Nooristan province.
Has the trail to bin Laden gone cold?
"I would have to say it probably has," says Grenier, who left the CIA in June.
Meanwhile, at the high-tech NCTC offices, Adm. Scott Redd says the emphasis on finding bin Laden overlooks important successes.
"Our intelligence has gotten better, our operations have gotten better," says Redd, director of the National Counterterrorism Center. "We've basically set [al-Qaida] back on their heels."
Redd argues that, despite five years of frustration, bin Laden's ability to mount attacks has been "substantially diminished," and he stresses the big picture view, beyond the al-Qaida leader, that his agency must take.
"We obviously are concerned about the effect he has," Redd concedes, "but there are no silver bullets. Taking out bin Laden doesn't end the war on terror. It would be a significant step, but it wouldn’t end the war on terror."